ComboBox控件OnSelchange消息
void XXXDlg::OnSelchangeCombo1()
{
CComboBox *p = (CComboBox *)GetDlgItem(IDC_COMBO1);
CString s;
p->GetLBText(p->GetCurSel(), s);
if(s=="多级子目录" )
GetDlgItem(IDC_COMBO2)->EnableWindow(TRUE);
else
GetDlgItem(IDC_COMBO2)->EnableWindow(FALSE);
}